These apparently break compilation on old MacOS toolchains, because the
MachO section name is capped to 16 chars (although, on my MacOS, at
least, the section name just gets truncated). Nevertheless, these serve
no purpose on non-ELF platforms (they're part of the LSB Linux ABI).
[Bug #20677]
We do not implement CET shadow-stack switching in amd64 Context.S. If
you compile Ruby with `-fcf-protection=full` and run it with
`GLIBC_TUNABLES=glibc.cpu.hwcaps=SHSTK` exported, it will crash with a
control flow exception.
Configure the appropriate notes at the end of Context.S
[Bug #18061]
When running on newer Intel processors supporting the feature,
OpenBSD enforces indirect branch tracking. Without this endbr64
instruction, jumps to the coroutine_transfer function result
in SIGILL on OpenBSD/amd64 when using such processors.
The OpenBSD Ruby ports have been using a patch similar to this
for the past two months.
From some research, cet.h has been supported by GCC for about
6 years and LLVM for about 4 years.
Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead. This would significantly
speed up incremental builds.
We take the following inclusion order in this changeset:
1. "ruby/config.h", where _GNU_SOURCE is defined (must be the very
first thing among everything).
2. RUBY_EXTCONF_H if any.
3. Standard C headers, sorted alphabetically.
4. Other system headers, maybe guarded by #ifdef
5. Everything else, sorted alphabetically.
Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).
It is more conventional to use compiler to pre-process and
assemble the `.S` file rather than forcing Makefile to use `.s`.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65952 b2dd03c8-39d4-4d8f-98ff-823fe69b080e